Quench gap structure



Oct. 6, 1964 D. o. MlsARE QUENCH GAP STRUCTURE 2 Sheets-Sheet 1 eee:

Filed NOV. 28, 1962 INVENTOR Dam/AL@ /W/SAZE BY t ArroeA/E Ys.

Oct. 6, 1964 n. o. MlsARE QUENCH GAP STRUCTURE 2 Sheets-Sheet 2 FiledNov. 28, 1962 z y f. w .J 'MN m m a0 f 0 m m m ,55 w/wf 7W@ m ZJ i K/.Il a, l R.. Nr /H//H////////////H/// :J I g .Mb/,m u 6 I, C 1 /f/ 4./ 06 United States Patent O 3,152,279 QUENCH GAP STRUCTURE Donald 0.Misare, Riverside, Ill., assigner to .Ioslyn Mfg. and Supply Co.,Chicago, Iii., a corporation of Iliinois Filed Nov. 28, 1962, Ser. No.240,701 11 Claims. (Cl. 313-231) The present invention relates to a newand improved quench gap structure, and more particularly to a sparkdischarge structure for insertion into an insulating housing of alightning arrester or the like.

Heretofore, it has generally been believed that initiation of a sparkdischarge gap close to the inner wall of a lightning arrester housingwould cause the spark discharge to deteriorate the housing insulation.However, it has been found, according to the present invention, thatwhen the spark discharge gap is appropriately confined with the sparkdischarge occurring close to the housing of the lightning arrester theinitial pressure build-up due to the spark discharge will tend to blowor force the spark discharge inwardly away from the wall of the housing.

Moreover, lightning arresters are in a highly competitive market and itis desirable that lightning arresters be readily and cheaply built toprovide an economical but efficient lightning arrester which may be soldat a cornpetitively low price.

Accordingly, it is an object of the present invention to provide a newand improved quench gap structure for use in a lightning arrester or thelike.

A further object of the present invention is to provide a new andimproved lightning arrester.

Yet another object of the present invention is to provide a quench gapstructure for a lightning arrester which may be readily and easilymanufactured to provide an economical and yet efhcient gap structurewhich may be competitively sold at low cost.

Further objects and advantages of the present invention will becomeapparent as the following description proceeds and the features ofnovelty which characterize the invention will be pointed out withparticularity in the claims annexed to and forming a part of thisspeciiication.

In accordance with these and other objects, there is provided animproved quench gap structure for use in a lightning arrester or thelike. Although the quench gap structure may be used in any suitablelightning arrester, specifically, the present quench gap structure maybe inserted into the lightning arrester disclosed in the copendingapplication of Edward H. Yonkers, Serial No. 157,293, filed November 16,1961. In accordance with the invention, the spark gap structure includesa gap assembly formed of a plurality of metal plates including a pair ofend plates and a selected number of intermediate plates. Theintermediate plates are formed with a pair of electrodes opposite eachother from the center of the plate and on opposite sides of the plate ata distance closer to the edge of the plate than to the center of theplate. Each electrode contains a surface extending inwardly toward thecenter of the plate. Adjacent plates are positioned with confrontingelectrodes forming a spark discharge gap therebetween. The plates areseparated by horseshoeshaped insulating spacers, each positioned betweenadjacent plates to separate and space the plates. The spark gaps and theplates form a current path through the gap assembly extending from oneplate to an adjacent plate approximately perpendicular to the platethrough the spark gap and then through the central area of the plate tothe next gap to describe a zig-zag path through the gap assembly. Thespacers are positioned between the plates with the open part of thespacers positioned adjacent the respective spark gap. The gap assemblyis held together by spring means. In a first embodiment the electrodesare formed by diametrically opposed dimples embossed near the edge ofthe plates so that the spark gap is closely spaced from the wall of thelightning arrester housing.

In another embodiment the electrodes comprise identical electrodesopposite each other from the center of the plate and formed from aprojection of the edge of the plate having a first portion extendingaway from the plane of the plate terminating in a spark discharging areaand including a spark running area extending inwardly from the sparkdischarging area toward the center of the plate terminating in an endportion spaced from the plate. Confronting electrodes form sparkdischarge gaps.

Advantageously, it will be appreciated that any selected number ofplates may be combined into a single lightning arrester to provide adesired kva. rating to the lightning arrester. Moreover, any reasonablekva. rating may be built from the identical components of the quench gapstructure merely by assembling more or less of the components into thedesired quench gap structure. It is therefore necessary to manufactureand stock but a single size and shape of component. Moreover, since thequench gap structure is readily formed with the plates being made ofstamped metal, the quench gap structure provides a very inexpensiveassembly which may be competitively priced.

Advantageously, it has been found in both of the embodiments, accordingto the present invention, that initial spark discharge in the spark gapcauses the spark discharge to move inwardly along the spark runningareas of the electrodes and away from the inner walls of the lightningarrester housing. Although the reason for this is not definitely known,it is believed that initial discharge creates a circumjacent pressurewhich first strikes the wall of the housing and then builds back towardthe discharge to blow the discharge inwardly toward the center of theplates. It will be appreciated that movement of the spark dischargeinwardly along the spark running area is effective to elongate the sparkand to provide for sharp cutoff and quickl cutoff of the discharge.

Moreover, although all embodiments of the present invention have beenfound to work satisfactorily, the second described embodiment, whereinthe current flow is to the edge of the plate and then down toward thespark discharging area and thereafter inwardly through the electrodealong the spark running area of the electrode, adds the force of theinduced magnetic field to move the spark discharge more positivelyinwardly along the running area and elongating and breaking the sparkdischarge.

For a better understanding of the present invention, reference may behad to the accompanying drawings, wherein:

FIG. 1 is a fragmentary cross-sectional view of a lightning arresteremploying the improved quench gap structure according to the presentinvention;

FIG. 2 is a cross-sectional view of the lightning arrester of FIG. 1,taken along line 2 2 thereof, and assuming that FIG. 1 shows the entirearrester;

FIG. 3 is a fragmentary cross-sectional view of a portion of the sparkgap structure of FIG. 1, taken along line 3 3 of FIG. 1;

FIG. 4 is a fragmentary cross-sectional view of the improved gapstructure of FIG. l, taken along line 4-4 of FIG. 3;

FIG. 5 is an exploded isometric View of the improved gap structure ofFIG. 1;

FIG. 6 is a fragmentary cross-sectional view of a lightning arresterusing a modified embodiment of a quench gap structure according to thepresent invention;

FIG. 7 is a cross-sectional view of the lightning aradriaan/a rester ofFIG. 6, taken along line '7-7 of FIG. 6, and assuming that FIG. 6 showsthe entire arrester;

FIG. 8 is a fragmentary cross-sectional view of a portion of theimproved spark gap structure of FIG. 6, taken along line 8 8 of FIG. 6;

FIG. 9 is a fragmentary cross-sectional view of a spark gap structure ofFIG. 7, taken along line 9-9 of FIG. 8; and

FIG. l is an exploded isometric view of the improved spark gap structureof FIG. 6.

Referring now to the drawings, and particularly to the embodiment ofFlGS. l through thereof, there is illustrated an improved isolating orquenching gap structure Ztl assembled in a lightning arrester 2l. Asheretofore described, the lightning arrester 2l may be of any suitabletype, for example, of the type disclosed in the aforementioned patentapplication of Yonkers, and may include a generally cylindrical housing22 of suitable insulating material such as clay or porcelain whichhouses not only the gap structure 2i) but additionally a characteristicelement 23, here shown as being of the valve type employing a nonlinearresistance or valving material of the type more fully described in theabove-mentioned Yonkers application. The gap structure 2) is seriallyconnected electrically between the characteristic element 23 and aterminal member 24 positioned at one end of the housing 22 by suitableend cap structure 25. An upper end of the gap structure 2% iselectrically connected to the end cap structure 25 and terminal member24E- through a compression spring 2S which additionally serves to holdthe components of the gap structure together, while the other end of thegap structure 24B rests on an electrically conductive support 29 whichadditionally serves to separate the gap structure 20 and thecharacteristic element 23.

In accordance with the present invention the quench gap structure 20comprises a gap assembly formed of a plurality of metal plates includinga pair of end plates 30a and Slb and a plurality of intermediate plates30C. As best illustrated in FIG. 5, the lower end plate 3tlg is formedof a circle, and the remaining plates are derived from the same sizecircle with two equal arcs of the circle for two opposed edges 3l and 32and equal chords of the circle for the remaining opposed edges 33 and34.

To provide a plurality of spark gaps 35 in the gap assembly, each of theintermediate plates 363C is provided with a pair of identical electrodes36 opposite each other from the center of the plate and on oppositesides of the plate located midway relative to edges 3l and 32,respectively, at a distance from the plate center greater than one-halfthe radius of the circle from which the plate is derived. The electrodes36 are formed by diametrically opposed dimples embossed near the curvedperiphery of the curved edges 3l and 32 of the plates. Each electrode isformed with a spark discharging area 36a, at its center and is providedwith a spark running surface 36]; extending inwardly therefrom. The endplates 30a and 30h are each provided with one electrode 36 identical tothose in the intermediate plates 30C. Adjacent ones of the plates arepositioned with an electrode of each plate confronting an electrode ofthe adjacent plate so that the spark discharge gap 35 is providedbetween the spark discharge areas 36a of confronting electrodes, and aspark running gap is formed between the spark running surface 36h ofconfronting electrodes and having an increasing length inwardly towardthe center of the plates.

For separating the plates 30a, Mtb, and 30e, there is provided aplurality of horseshoe-shaped ceramic type insulating spacers 4t). Eachof the spacers 4t) is of somewhat U-shape, open at one end. The spacers46 are positioned with the open part adjacent the respective spark gap35 between the separated plates. Moreover, to provide for adequatelylocating the plates 30a, 30h, and 30C, and the spacers 40 relative toeach other, the

plates are provided with a plurality of aligning bosses il and thespacers iti are provided with corresponding detents i2 to provide forquick and ready alignment of the members. If desired, the spacers 40 maybe of ceramic type resistor material. The plates 30a, 30h, and 30C maybe provided with holes or other preforations therein preferably nottouching the spacers 4t).

As heretofore described, the compression spring 28 is effective to biastogether the elements of the gap assembly structure.

It will be understood in operation that the spark gap 35 and plates 36a,30h, and 30C form a current path extending from one plate to an adjacentplate through the spark gaps 35 approximately perpendicular to theplates, to the spark gap, and then through the central area of theplates to the next gap to describe a Zig-zag path through the gapassembly. Although it would be expected that a spark formed in the sparkgap 35 close to the inside surface of the housing 22 would deterioratethe housing 22, unexpectedly it has been found that in actuality a sparkformed in the spark gap 35 is blown inwardly toward the center of theplates where it is extended between the spark running surfaces 36h ofconfronting electrodes 36 and quickly extinguished.

Although a lightning arrester according to the abovedescribed embodimenthas been found to operate quite satisfactorily, it has further beenfound that the induced magnetic force of a owing current can be used tofurther push the arc inwardly along its expanding gap to more readilyextinguish the arc. This is accomplished by the gap structureillustrated in the embodiments of FIG. 6 through lO. As thereinillustrated, there is shown an improved gap structure 50 according toanother embodiment of the present invention. The gap structure 50 isassembled in a lightning arrester 51 which, as heretofore described,includes a cylindrical housing 52 of suitable insulating material andincluding a characteristic element 53 of the type heretofore described.The gap structure Sti is serially connected electrically between thecharacteristic element 53 and a terminal member 54 of the lightningarrester 51, which is secu-red to the housing 52 by an end cap structure55. A compression spring 58 is effective not only to electricallyconnect the gap structure 50 with the terminal member 54 and the end capstructure 55, but additionally to compress the elements of the gapstructure 50 into assembled relation. The lower end of the gap structure50 rests on an electrically conducting support 59 which is effective tointerconnect the gap structure 50 with the characeristic element 53.

Referring now to the improved gap structure 50 according to the presentinvention, the gap structure 50 cornJ prises a plurality of metal platesincluding a pair of end plates 60a and 6019 and a plurality ofintermediate plates 60C. As heretofore described, each of the plates60a, 6tlb, and 60e is derived from a circle with two equal arcs of thecircle for two opposed edges 61 and 62, FIG. l0, and equal chords of thecircle for two remaining edges 63 and 64.

To provide for a spark gap 65 between adjacent ones of the plates 60a,60h, and 60C, each of the intermediate plates 66C are formed with a pairof electrodes 66, and each of the end plates 60a and 60b are formed withan identical electrode 66. The electrodes 66 on the intermediate platesare opposite each other from the center of the plate on opposite sidesof the plate midway along the straight edges 63 and 64 formed by thechords of the circle, while the electrode in the respective end plates60a and 6tlb extends in one direction from the plate midway relative toa respective edge 63 and 64 formed by a chord of the circle. Eachelectrode 66 is shaped from a projection extending from the chord edge63 or 64 of the plate and is provided with a first portion extendingaway from the plane of the plates and terminating in a spark dischargearea 66a, FIGS. 6 and 10. Moreover, each of the electrodes 66 includes aspark running area 66h extending inwardly from the spark discharging'area toward the center of the respective plate terminating in an endportion spaced from the plate. It will be understood that adjacentplates have confronting elec-trodes 66 establishing the spark gap 65therebetween which has the spark discharging area 66a and the sparkrunning area 66h of increasing length inwardly toward the center of theplate.

To provide for separating and spacing the plates 66a* 601;, and 60Crelative to each other, there is provided a plurality of horseshoeorC-shaped spacers 'itl formed of a circle of the same exterior radius asthe curved portions of the plates 69a, ilb, and 60C, of suitableelectrically insulating material. The spacers 70 are each formed with anopen end positioned adjacent to, and equally spaced from the respectivespark gap 65 between the respective pairs of separated plates. Moreover,in order to adequately align and locate the plates 60a, del), and 69C,and the spacers 7i?, the plates and spacers are provided with aplurality of interitting bosses 71 and de-tents 72.

ln operation, the gap structure 5t) initially is similar to the gapstructure 2t) heretofore described. It will be appreciated that thespark gaps 65 and the plates 60a, tlb, and 60C form a current pathextending from one plate to an adjacent plate approximatelyperpendicular to the plate through the spark gap and then through thecentral area of the plate to the next gap to describe a zig- Zag paththrough the gap assembly. Moreover, in like manner as heretoforedescribed in connection with the embodiment of FIGS. 1 through 5,immediately upon initiation of the spark discharge in the spark gap 65,spark discharge is blown inwardly from the spark discharge area 66aalong the spark running surface 66h thereby to elongate the discharge toaid in terminating the spark discharge.

In the embodiment of FGS. 6 through 10, once the spark discharge hasmoved a minute distance from the spark discharge area 66a along thespark running area deb, then the current ow through the plates will beoutwardly from the discharge through the spark running sun faces 661;and spark discharge surfaces 66a, then inwardly toward the respectiveplates and across extending along the plate from one electrode 66 to theopposite electrode 66. The magnetic field set up by the current owing inthe running surface 6617 outwardly to the periphery of the plate will beeffective to establish a magnetic field which tends to drive thedischarge inwardly along the running surface 66h to aid the blowing ofthe discharge inwardly. thereby extending and terminating the discharge.

The quench gap struc-ture according to the present invention may beassembled in any desired ratting merely by selection of the requirednumber of intermediate plates in the assembly. This is readilyaccomplished without the necessity of stocking additional componentparts. Moreover, in view of the travel ofthe spark discharge inwardlyaway from the inner surface of the lightning arrester housing, a veryinexpensive gap structure may be made from simple sheet electrodeelements. Additionally, the pressure build-up bouncing from the innerwall of the lightning arrester housing which blows the spark dischargeinwardly toward the center of the gap structure is also effective toprevent overheating and deterioration of the housing by the hotdischarge.

Although the present invention has been described by reference tovarious embodiments thereof, it will be apparent that numerous othermodifications and embodiments may be devised by those skilled in theart, and it is intended by the appended claims to cover all suchmodiications and embodiments which fall within the true spirit and scopeof the present invention.

What is claimed as new and desired to be secured by Letters Patent ofthe United States is:

1. A quench gap structure for insertion into a ceramic housing of alightning arrester or the like and comprising a gap assembly forinsertion in the housing formed of a plurality of metal plates includinga pair of end plates and at least one intermediate plate, at least theintermediate plates deriving from a circle with two equal arcs of thecircle for two opposed edges and equal chords of the circle for theremaining two edges, each intermediate plate being formed with a pair ofidentical electrodes opposite each other from the center of the plateand on opposite sides of the plate located midway relative to an edge ata distance from the plate center greater than onehalf the radius of saidcircle, at least one surface of each electrode extending inwardly towardthe center of said plate to form a spark running area, adjacent ones ofsaid plates being positioned with one electrode of each plateconfronting an electrode of the adjacent plate to form a spark dischargegap therebetween, said end plates each being provided With one electrodeidentical lto each of the above described electrodes and positionedtoward a confronting electrode in an adjacent plate, said spark gaps andsaid plates forming a current path extending from one plate to anadjacent plate approximately perpendic ular to said plate through saidspark gap and then through the central area of the plate -to the nextgap to describe a zig-zag path through the gap assembly; and a pluralityof horseshoe-shaped ceramic type insulating spacers, each positionedbetween adjacent plates to separate and space said plates, the open partof said spacers being positioned toward the edge adjacent the respectivespark gap.

2. A quench gap structure as set forth in claim 1 above wherein thenumber of said intermediate plates is selectable to provide a desiredquench gap voltage capacity.

3. A quench gap structure as set forth in claim 1 above wherein saidplates and said spacers are provided with bosses and detents to providefor aligning the same.

4. A quench gap structure as set forth in claim 1 above wherein saidspacers are ceramic type resistor spacers.

5. A quench gap structure as set forth in claim 1 above and includingspring means biasing said plates and spacers together.

6. A quench gap structure as set forth in claim l above wherein saidelectrodes are formed by diametrically opposed dimples embossed near thecurved periphery of the curved edges of the plates.

7. A quench gap structure as set forth in claim 6 above wherein saidspacers are somewhat U-shaped generally conforming to the shape of theintermediate plates.

8. A quench gap structure for insertion into a ceramic housing of alightning arrester or the like comprising a gap assembly for insertionin the housing formed of a plurality of metal plates including a pair ofend plates and at least one intermediate plate, at least theintermediate plates deriving from a circle with two equal arcs of thecircle for two opposed edges and equal chords of the circle for theremaining two edges, each intermediate plate being formed with a pair ofidentical electrodes opposite each other from the center of the plateand on opposite sides of the plate located midway relative to an edgealong the edges formed of chords, and shaped from a projection of saidedge having a first portion extending away from the plane of said plateterminating in a spark discharging area, and including a Spark runningarea extending inwardly from the spark discharging area toward thecenter of the plate terminating in an end portion spaced from the plateto form a spark running area, adjacent ones of said plates beingpositioned with one electrode of each plate confronting an electrode ofthe adjacent plate to form a spark discharge gap therebetween, said endplates each being provided with one electrode identical to each of theabove-described electrodes and positioned toward a confronting electrodein an adjacent plate, said spark gaps and said plates forming a currentpath extending from one plate to an adjacent plate along said sparkrunning gap outwardly of said plates through said first portion and theninwardly through said plate and through the central area of said plateto the next electrode structure; and a plurality of horseshoe-shapedceramic type insulating spacers, each positioned between adjacent platesto separate and space said plates, the open part of said spacers beingpositioned toward the edge adjacent the respective spark gap.

9. A quench gap structure as set forth in claim S above wherein saidspacers are somewhat C-shaped having an outer periphery approximatelyequal to the radius of said circle.

10. A quench gap structure for insertion into an insulated housing of alightning arrester or the like and comprising a gap assembly formed of aplurality of metal plates including a pair of end plates and at leastone intermediate plate, at least said intermediate plates being formedwith a pair of electrodes opposite each other from the center of theplate and on opposite sides of the plate at a distance closer to theedge of the plate than to the center of the plate, each electrode beingprovided with a surface extending inwardly toward the center ot saidplate, adjacent plates being positioned with confronti ing electrodesforming a spark discharge gap therebetween, and a plurality ofhorseshoe-shaped insulating spacers, each positioned between adjacentplates to separate and space the plates.

1l. A quench gap structure for insertion into a ceramic housing of alightning arrester or the like and comprising a gap assembly forinsertion in the housing formed of a plurality of metal plates includinga pair of end plates and at least one intermediate plate; eachintermediate plate being formed with a pair of identical electrodesopposite each other from the center of the plate and on opposite sidesof the plate at a distance from the plate center greater than one-halfthe distance to the edge, at least one surface of each electrodeextending inwardly toward the center of said plate to form a Sparkrunning area, adjacent ones of said plates being positioned with oneelectrode of each plate confronting an electrode ot the adjacent plateto form a spark discharge gap therebetween, said end plates each beingprovided with one electrode identical to each of the above describedelectrodes and positioned toward a confronting electrode in an adjacentplate, said snarl; gaps and said plates forming a current path extendingfrom one plate to an adjacent plate approximately perpendicular to saidplate through said spari; gap and t'nen through the central area of theplate to t .e next gap to describe a zig-zag path through the gapassembly; and a plurality of insulating spacers, each positioned betweenadjacent plates to separate and space said plates.

References Cited in the file of this patent UNITED STATES PATENTS2,623,197 Kalb Dec. 23, 1952 3,106,662 Cunningham Oct. 8, 1963 FOREIGNPATENTS 264,187 Great Britain Apr. 2l, 1927

10. A QUENCH GAP STRUCTURE FOR INSERTION INTO AN INSULATED HOUSING OF ALIGHTNING ARRESTER OR THE LIKE AND COMPRISING A GAP ASSEMBLY FORMED OF APLURALITY OF METAL PLATES INCLUDING A PAIR OF END PLATES AND AT LEASTONE INTERMEDIATE PLATE, AT LEAST SAID INTERMEDIATE PLATES BEING FORMEDWITH A PAIR OF ELECTRODES OPPOSITE EACH OTHER FROM THE CENTER OF THEPLATE AND ON OPPOSITE SIDES OF THE PLATE AT A DISTANCE CLOSER TO THEEDGE OF THE PLATE THAN TO THE CENTER OF THE PLATE, EACH ELECTRODE BEINGPROVIDED WITH A SURFACE EXTENDING INWARDLY TOWARD THE CENTER OF SAIDPLATE, ADJACENT PLATES BEING POSITIONED WITH CONFRONTING ELECTRODESFORMING A SPARK DISCHARGE GAP THEREBE-